SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54d0fe3d47e23700cd128474e101e8287dc0aa27756a5934e653f6ca555e6494' 
  AND token = '3LZJ1Tjorq+FMryIInogRbmaFiwAfdxwF+QbsiNpf0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}