SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f267d9163bd2d0a9b0fb0f9b6ccf2c5f0438bc80ca9b0f6a6408d0b78fa0dc17' 
  AND token = 'RpasZiWyjFRLfaiewsJ1XZaUvb1p2chY7iQbYox+98g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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