SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f56bda9034424de3460cac84ea94ad92b0d6bdf11e84e41ecd107efbcfc11243' 
  AND token = 'I+dc+S4vfaITMP0eARrNmcjIWDz1ImITul+Qv0jYhVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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