SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26b08092aad3259ad37c63356ad75f44a45e62e68d9536d0aa877663e7b5b1da' 
  AND token = 'MohGIk876CIc5e32gy5U/WZQ5JXlQlzIRqhYbSOQhW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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