SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cfe2f64078e27406cb9ab3267b12c18d7a4772dd287a1bd13b359ba2ff744ac' 
  AND token = '+Hf0Mmq/eAgOrlEOKxQPxjcz4YpwmN2NKnQldLBw/mM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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