SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31555b9fbba3b3964dc3596a118fc502c89035c1af1ecdc3e61f6cf999c2f1ee' 
  AND token = 'RNt13tHyVBnpKJlIQxoPK3ZJymOEO4GeO/KR/I7MZ7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}