SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f664cb661c2b966486bfcb60af53a9727224a88fc775d4d94c3e486d97291968' 
  AND token = '4VpLgMqGpEH4yqc1j/j/waY/IFtqPekA5du+hi3OEb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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