SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e35a95403e8d560fb5aa0ed2a1fcf7041e32c8ccb3b6ad15a13da8a3a711ee25' 
  AND token = 'o3qU1GGs1U561HaMyL9M19hY+8mLdrbLhvpm4HnCLWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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