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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'abf0fe2fb9500a13b3fa8f3f9a0ddecb4f42476807bd9607b389ba81fd80b8aa' 
  AND token = 'o3r5bHC3t4y9pxVs4fk3awnCSf0rXFvjj+RgMEkfP+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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